This paper presents a mathematical model able to predict the water barrier properties of nylon film as a function of the water activity at the upstream and downstream side of the film. To validate the model, water sorption and permeation tests were conducted at 25 °C. The fitting and predictive ability of the proposed model was successfully tested by fitting the model to the sorption data and by predicting the nylon water permeability coefficient, respectively. The implications of the adopted approach on practical aspects of packaging were pointed out by comparing the nylon water barrier properties as evaluated by means of a permeation test and that in the real working conditions.

Understanding environmental impacts of complete food supply chains is important for the food industry to help devise strategies for reducing the impacts of current and future products. Breakfast cereals are one of the most important foods consumed in many countries, but their environmental impacts are currently unknown. Therefore, this study explores the environmental sustainability issues in the food–energy–water nexus by considering breakfast cereals manufactured by one of the world’s largest producers, Kellogg Europe. A life cycle assessment has been carried out for these purposes with the aim of helping the Company to integrate environmental sustainability considerations into the design of their products and packaging. The results indicate that the average global warming potential (GWP) of Kellogg’s breakfast cereals is 2.64 kg CO2 eq. per kg of product. The main GWP hotspots are the ingredients (48%) and energy used in the manufacturing process (23%); packaging and transport contribute 15% each. Rice is the single largest contributor to the GWP of the ingredients (38%). The manufacturing stage is the main contributor of primary energy demand (34%), while the ingredients are responsible for more than 90% of the water footprint. The ingredients are also the main contributors to most other environmental impacts, including land use (97%), depletion of elements (61%), eutrophication (71%), human toxicity (54%) and photochemical smog (50%). The impacts from packaging are high for freshwater and marine toxicity. The contribution of transport is significant for depletion of elements and fossil resources (23%), acidification (32%), ozone depletion (28%) and photochemical smog (24%). Improvement opportunities explored in the paper include better agricultural practices, recipe modifications, improved energy efficiency of manufacturing processes and use of alternative packaging. Impacts from consumption are also discussed.

In this paper we have shown that one of the most important characteristic of a packaging is protection of the wrapped product from the influences of the outer. A special emphasis has been put on the analysis of the importance of a packaging in the preventing steam and oxygen harm the product itself.

The consequences of humidity exchanges between food and environment are always very important for the preservation of microbiological and sensorial quality of the product. For a realistic shelf-life evaluation of sensitive food-products is therefore essential to know exactly the water vapour transmission rate (WVTR) through the packaging material. The measurement of this important diffusional property is commonly performed without regard of the exchange direction and in conditions very far from those of reality: extremes temperature and humidity combinations as 38 deg C and 90% of RU. Thus, it was considered useful and interesting to verify if the permeability phenomenon could be affected by the direction of flow and by the contact of dry or moist product. To such purpose, measures of water vapour permeability were realized using PET and OPP pouches, filled with water or calcium chloride. The results achieved excluded the influence of the contact of dry or wet substances with the pouches walls and of the flow direction on the determination of the WVTR for the materials and the conditions examined | Le conseguenze di uno scambio di umidita' tra alimento ed ambiente risultano sempre molto importanti per la conservazione della qualita' biologica ed organolettica del prodotto. Per una reale valutazione della conservabilita' dei prodotti alimentari sensibili all'umidita' e' quindi essenziale conoscere la velocita' di trasmissione al vapore acqueo (WVTR) attraverso il materiale di confezionamento. I metodi convenzionali di misura di questa importante proprieta' diffusionale sono solitamente riferiti a condizioni lontane da quelle reali sia per le combinazioni temperatura-umidita' relativa in cui si effettuano le determinazioni (38 gradi C e 90% di UR), sia per quanto riguarda le modalita' in cui il fenomeno di permeazione avviene. Non si tiene infatti in considerazione ne' la direzione di flusso del vapore d'acqua, ne' che nel caso reale il prodotto (umido o secco) si puo' trovare a diretto contatto con il materiale. Si e' cosi' ritenuto importante poter verificare se il fenomeno di permeabilita' fosse influenzato da queste condizioni e dalla direzione del flusso. A tal fine si sono effettuate misure di permeabilita' impiegando buste realizzate con PET ed OPP, riempite con acqua o cloruro di calcio. I risultati ottenuti hanno escluso l'influenza del contatto e della direzione di flusso sulla determinazione della WVTR per i materiali e le condizioni considerate

Compatibility of CNF with three polysaccharides having different surface charges and backbones (chitosan, methyl cellulose, and carboxymethyl cellulose) was investigated. Chitosan (CH) incorporation reduced water absorption (WA) of CNF films (P < 0.05). CH molecular weight (Mw) (68, 181, 287 kDa) and amount (10 and 20 g/100 g CNF in dry basis) impacted moisture barrier, mechanical, antibacterial, thermal, and structural properties of CNF films. Regardless of Mw, CH incorporation (20 g/100 g CNF) decreased (P < 0.05) WA of CNF films, and high Mw (287 kDa) CH (20 g/100 g CNF) incorporation resulted in lower film water solubility while increasing film water vapor permeability compared with low Mw CH (68 kDa) incorporation (P < 0.05). CNF film with low Mw CH (20 g/100 g CNF) exhibited antibacterial activity against L. innocua and E. coli. Interaction mechanisms between CH and CNF were investigated through thermal, structural, and morphology analyses using DSC, FTIR, and SEM, respectively. CNF films with low or high Mw CH incorporation (20 g/100 g CNF) were further validated as surface contact films for fresh beef patties, showing effectiveness to prevent moisture transfer between the layered patties. This study demonstrated the potential of using CNF-CH composite films as water resistant and antibacterial packaging for foods with high moisture surfaces.